The invention concerns a generic cleaning device for a laboratory fermenter according to the preamble of the main claim, namely such a device for a laboratory fermenter for growing microorganisms such as bacterial or fungal cultures or cell cultures, where the laboratory fermenter is provided with a gas supply connection which is called a sparger and which is connected to a line reaching into the nutrient solution, with an exhaust connection leading to the gas space located over the nutrient solution and in given cases connected to an exhaust cooler on the Outer side of the laboratory fermenter, and with a withdrawal connection for the nutrient solution or cleaning fluid and leading to the lowest point in the fermenter. Along with this the laboratory fermenter can comprise additional components known per se, such as a stirring mechanism, measurement sensors, heating, and the supply of base, acid, AF, feed, etc. via pumps and push valves as well as air supplies of less than 1, preferably 0.5 bar.
Such a cleaning device for parts of laboratory fermenter with a holding capacity up to ca. 30 liters is known per se as an autoclave.
In order to be able to clean this laboratory fermenter after it has been used, it is necessary to disassemble it and first clean the smaller parts, then place them in an autoclave, and finally autoclave them. After the sterilization in this manner has been completed the parts must be re-assembled in the sterile state so that the laboratory fermenter is once again ready for use. This known type of churning requires more than an entire day and moreover must be done by a technician in a chemical laboratory. Thus the cleaning of laboratory fermenters consumes considerable resources.
The object of the invention is thus to provide a laboratory fermenter cleaning device which consumes fewer resources in its operation.
The inventive laboratory fermenter cleaning device includes three cleaning connections, namely an immersion pipe connection and two gas connections, each gas connection is conducted to an intermediate switch valve having an outlet, each intermediate switch valve has two switch positions, namely a cleaning start position letting the gas connection open to the outlet and a cleaning end position closing this connection, the cleaning connections are connected via lines to control valves, a pump, a filter, and by a cleaning control which manages the cleaning process to an air connection, a water connection, and a waste water connection, where the lines are formed as hose lines, the valves as hose pinch valves, and the pump as a hose pinch pump.
The cleaning device transportable according to the invention is connected by its immersion pipe connection to the withdrawal connection and by its two gas connections, via the intermediate valves in the cleaning start position, to the gas supply connection and the exhaust connection of the laboratory fermenter to be cleaned. After introducing a base, e.g., sodium hydroxide solution and/or water, into the laboratory fermenter for the purpose of cleaning it, in that cleaning process the mixture, in given cases reversing its flow direction and in given, cases adding water from the water connection, is circulated for a sufficiently long time, then neutralized by adding acid, e.g., phosphoric acid, and finally, by adding air into the gas space via the withdrawal connection of the laboratory fermenter, transported to the immersion pipe connection and ultimately to the waste water connection which can be connected to waste water tank (a so-called kill tank). After the end of the cleaning process all the hose connections to the laboratory fermenter can be separated and in given cases closed at the cleaning connections, leaving the intermediate valves still in their cleaning start position on the laboratory fermenter, which is then completely cleaned and ready for a new fermentation cycle without being disassembled into parts and autoclaving of the same being necessary. The cleaning device according to the invention can also be provided internally with a water tank and also a waste water tank as well as an electric battery for the pump and the cleaning control. It is also possible that, external tanks and the electric AC power supply may be used instead of internal power and waste water features.
So that the cleaning work is not shifted from the laboratory fermenter to the cleaning device according to the invention, all and thus all interrelated hose lines are separated in the manner of a hose line tree as a hose line set from the hose pinch valves and the hose pinch pump after being used several times and replaced with a hose line set which is new and clean, but not necessarily sterile because the hose line set is cleaned and sterilized by the base rinsed through initially wherewith the cleaning device can also be used once again for the next cleaning process.
Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of one or more preferred embodiments when considered in conjunction with the accompanying drawings.